Head to head
Which one will break you first?
Two fingerprints on one grid. Both are scored through your profile, so this answers the question for you rather than for the average player.
Age of Empires II: Definitive Edition is the harder of the two for you, by 3.1 points. The gap is widest on strategy, where Age of Empires II: Definitive Edition asks considerably more than The Witcher 3: Wild Hunt. If you want the gentler run, start with The Witcher 3: Wild Hunt.
Axis by axis, biggest gap first
THE WITCHER 3: WILD HUNT
Combat that yields immediately to a difficulty slider, wrapped around a preparation system the game quietly assumes you will ignore.
Relaxed. Failure is rare and cheap.
AGE OF EMPIRES II: DEFINITIVE EDITION
Build orders are the curve, and the campaigns teach almost none of what the game actually asks for. The hard AI does not forget its economy while it fights.
Sustained pressure. Progress is earned.